Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars Express - 5000 orbits and counting

23.11.2007
On 25 December 2003, Europe’s first Mars orbiter arrived at the Red Planet. Almost four years later, Mars Express continues to rewrite the text books as its instruments send back a stream of images and other data. Today, the spacecraft reached another milestone in its remarkable career by completing 5000 orbits of Mars.

During its mission to investigate martian mysteries, the orbiter has revolutionised our knowledge of Mars, probing every facet of the Red Planet in unprecedented detail. Some of the most visually astonishing results have been returned by the High-Resolution Stereo Camera (HRSC), which has produced breathtaking, 3D colour images of the diverse martian surface – with giant volcanoes to sinuous valleys and ice-modified craters.


An artist's impression of Mars Express. The spacecraft left Earth for Mars on 2 June 2003. It reached its destination after a 6-month journey, and has been thoroughly investigating the planet since early 2004. Credits: ESA - D. Ducros

One of the most surprising discoveries has been the youthful appearance of the country-sized volcanoes of the Tharsis ridge, suggesting they may have been active only a few million years ago. The images also show that glacial landforms are widespread over much of the planet, with glacial activity continuing in some areas until perhaps 20 000 – 30 000 years ago. Among the peculiar landforms imaged by HRSC is what appears to be a recently frozen body of water in Elysium, close to the equator.

While the camera has been imaging the surface in exquisite detail, other instruments have been examining different aspects of the planet’s environment. One of the most significant results from the Visible and Infrared Mineralogical Mapping Spectrometer OMEGA has been the discovery of clays, hydrated minerals that formed early in the planet’s history, when liquid water was fairly abundant. However, the presence of sulphates and iron oxides suggests that the planet subsequently became colder and drier, with only episodic eruptions of water onto the surface.

At the poles, OMEGA has measured the surface composition and produced unprecedented maps of water ice and carbon dioxide ice. Further insights into the martian poles have come from the Mars Advanced Radar for Subsurface and Ionospheric Sounding, MARSIS, which is revealing, for the first time, the secrets of the planet’s subsurface.

It has so far identified the presence of water ice deposits several kilometres underground and revealed fine, layered material near the poles. Similar soundings of the north polar cap have confirmed that it is dominated by water ice, with variable amounts of dust. The larger southern cap seems less dusty, but, with a maximum thickness of 3.7 km, it contains enough ice to produce a global ocean 11 m deep.

The multi-frequency radar has also been probing the upper atmospheric layer (the ionosphere) and found that the distribution of charged particles is linked with patchy magnetic fields in the martian crust.

Although Mars’ atmosphere is very thin, it plays an important role in the planet’s evolution, and new breakthroughs have been made possible by Mars Express. The Planetary Fourier Spectrometer (PFS) has made the most complete map to date of its chemical composition. Evidence for the presence of methane could indicate that volcanic activity, or even simple lifeforms may still be present today.

Meanwhile, the Ultraviolet and Infrared Atmospheric Spectrometer, SPICAM has provided the first complete vertical profile of the atmosphere’s carbon dioxide density and temperature. It has revealed a nightglow and aurorae at mid-latitudes, produced the first ozone map and discovered the highest clouds ever observed on Mars.

The Energetic Atoms Analyser (ASPERA) has confirmed that the solar wind is slowly stripping atoms from the atmosphere down to an altitude of 270 km, although the rate of loss is surprisingly slow.

The MaRS radio science experiment has studied surface roughness by pointing the craft’s high-gain antenna at the planet and recording the echoes. It has also been used to measure small changes in the spacecraft’s orbit caused by gravity anomalies. Some of the most marked increases in surface gravity have been found over the volcanic Tharsis ridge, indicating a higher-than-average crustal density. Another discovery has been the existence of an ionospheric layer created by meteors burning up in the atmosphere.

With the mission already extended until at least 2009 and the possibility of further extensions into the next decade, ESA is keen to ensure that Mars Express will continue to provide the best possible scientific return. In an effort to meet the needs of the various science teams with instruments on Mars Express, controllers at ESA’s Space Operations Centre in Darmstadt, Germany, are currently fine-tuning the spacecraft’s orbit.

“Between 18 November and 16 December, the thrusters will be fired five times to make minor alterations to the orbit,” said Tanja Zegers, Mars Express Science Operations Co-ordinator.

“This will ensure that HRSC and OMEGA will continue to have suitable lighting conditions for their observations in the future, while meeting the needs of the MARSIS scientists, who need observing time at night to look beneath the surface. It will also enable the imaging instruments to continue their programme of detailed observations, so that they can eventually complete the global mapping of the planet.”

Agustin Chicarro | alfa
Further information:
http://www.esa.int/SPECIALS/Mars_Express/SEM3OQ63R8F_0.html

More articles from Physics and Astronomy:

nachricht Astrophysicists measure precise rotation pattern of sun-like stars for the first time
21.09.2018 | NYU Abu Dhabi

nachricht Halfway mark for NOEMA, the super-telescope under construction
20.09.2018 | Max-Planck-Institut für Radioastronomie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells

21.09.2018 | Life Sciences

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>